1. Field of the Invention
The present invention relates to the operation of a closure normally operated by a motor and, more particularly, to an auxiliary device for allowing manual operation of the closure.
2. Description of the Prior Art
It is well known in the art of closures operated by way of electric motors to provide each system with an auxiliary operating device to permit manual operation of the closure in the event, for instance, of a failure of the electric motor.
Canadian Patent No. 2,112,350 issued on Feb. 22, 2000 in the name of Manaras et al. discloses such an auxiliary closure operating device which is mounted on a motor driving an output shaft adapted to open and close a closure, such as a garage door. The auxiliary operating device comprises a shaft mounted for rotational and axial movements within an elongated surrounding sleeve supported on the motor. A first gear is mounted at a first end of the shaft for rotation therewith. In its idle position, the first gear is engaged by a locking finger in order to prevent rotational movement of the shaft. A pulley is mounted for free rotation at the opposed end of the shaft and is engaged with a manual chain. A disc is mounted to the hub of the pulley for engaging a cam member fixedly mounted to the shaft adjacent the pulley. The initial rotational movement induced to the pulley via the manual operation of the chain causes the disc to displace along the cam member so as to push the latter away from the pulley, thereby causing the shaft, which is locked against rotation due to the engagement of the locking finger with the first gear, to slide axially within the sleeve. At one point, the first gear will disengage from the locking finger and will mesh with a second gear secured to the output shaft, thereby allowing the shaft to rotate with the cam member in order to drive the output shaft. At the same time, the disc will engage a stopper on the cam member such that further rotation of the pulley will be transmitted as a torque to the cam member, thereby causing the rotation of the shaft and of the first gear and, thus, of the second gear and of the motor's output shaft.
Canadian Patent Application No. 2,297,220 published on Mar. 15, 2001 discloses a more compact auxiliary operating device wherein the manually actuated pulley is directly mounted on the shaft normally driven by the motor. The pulley has an axially extending hub fitted with a roller mounted on a radially extending idle axle. The roller travels on a cam surface of a cam mounted on the normally motor-driven shaft. The action of the roller on the cam causes the cam to move axially on the shaft towards a spring pin extending radially from the shaft. The engagement of the cam with the spring pin permits to transmit a torque from the pulley to the shaft via the cam.
One problem with the two above-described auxiliary operating devices resides in the lack of flexibility that they offer during installation. For instance, if the device has been configured to be installed on the right side of a closure and that once on site the technician realized that the device can only be mounted on the left side of the closure, then the device must be completely disassembled and reconfigured to permit the installation thereof on the left side of the closure.